Re: [PATCH v2 18/19] block/nvme: Switch to using the MSIX API

[Auger Eric]

Hi Philippe,

On 10/26/20 11:55 AM, Philippe Mathieu-Daudé wrote:
> In preparation of using multiple IRQs, switch to using the recently
> introduced MSIX API. Instead of allocating and assigning IRQ in
> a single step, we now have to use two distinct calls.
> 
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  block/nvme.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index 46b09b3a3a7..191678540b6 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -693,6 +693,7 @@ static int nvme_init(BlockDriverState *bs, const char 
> *device, int namespace,
>      size_t device_page_size_min;
>      size_t device_page_size_max;
>      size_t iommu_page_size_min = 4096;
> +    unsigned irq_count = MSIX_IRQ_COUNT;
>  
>      qemu_co_mutex_init(&s->dma_map_lock);
>      qemu_co_queue_init(&s->dma_flush_queue);
> @@ -809,8 +810,17 @@ static int nvme_init(BlockDriverState *bs, const char 
> *device, int namespace,
>          }
>      }
>  
> -    ret = qemu_vfio_pci_init_irq(s->vfio, s->irq_notifier,
> -                                 VFIO_PCI_MSIX_IRQ_INDEX, errp);
> +    ret = qemu_vfio_pci_msix_init_irqs(s->vfio, &irq_count, errp);
> +    if (ret) {
> +        if (ret == -EOVERFLOW) {
> +            error_append_hint(errp, "%u IRQs requested but only %u 
> available\n",
> +                              MSIX_IRQ_COUNT, irq_count);
This message can be directly printed in qemu_vfio_pci_msix_init_irqs()
> +        }
> +        goto out;
> +    }
> +
> +    ret = qemu_vfio_pci_msix_set_irq(s->vfio, MSIX_SHARED_IRQ_IDX,
> +                                     s->irq_notifier, errp);
>      if (ret) {
>          goto out;
>      }
> 
Thanks

Eric